Thursday, October 15, 2009

The very lightest and darkest parts of an image can often be difficult for a digital camera to capture. Especially if the scene has strong contrast in the lighting, or perhaps looking directly at the sun. The technical reason is that most digital cameras only have a limited dynamic range (the way in which it captures the lightest value to the darkest). When the scene has a wider range of lighting the camera light meter is forced to select the range that it will best try to expose. If it choose to expose for the shadow (as you have pointed the camera there) the lightest parts get over exposed. Point at the darkest areas will leave the shadows dark and without detail.

This series was taken using Bracketing with 0.5 steps in EV

The first way to overcome the dynamic range limitation of your camera is to take a series or bracketted exposure setting (ie with different EV values) Like the set above and hope that at least one of them will turn out Ok! Trouble is the image with the best sky has the land mass in detail-less shadow and the one showing detail of the beach has the sky bleached out.

The technique know as HDRi (which I have mentioned before) lets you combine each of these separate exposures and make up a new image that contains the detail from the extended tonal range. In this case I have used Dynamic Photo and tone mapping to match the range of the human eye. And now I have a photo that looks like the scene I was trying to take.

Wednesday, October 14, 2009

Basically I'm just testing how the flickr blog this button work now. Well it still seems to work much the same. Your still have to go into You/ Your Account/ Personal Information/ Extending Flickr/ Your Blogs to be able to change the format & layout. Still tedious and not exactly user friendly. So it would still easier to go into the all sizes menu, select the size you want and cut & paste the HTML link into your blog.

Tuesday, October 13, 2009

One of the new features in Picasa 3.5, is geotagging directly via google maps. You where previously able to geotag via google earth, and you still can. To test this I choose this photo of a monument in the main street of Leura, in the Blue Mountains, as it was something I could easily see in the google map hybrid image. Geotagging in Picasa no longer requires looking for a separate function among the tools and opions. Just select the photo (or photos in album mode) you want to locate. Then press the places button, it down on the lower right of the picasa window. A google map is displayed in the places widow that pops up. Simply navigate to where the photo was taken. This can be using the map zoom and panning controls, or type in an address, or location name to the search box at the bottom of this places window. Using the hybrid or satelite display option you can get street level detail and I could easily find the place I took my picture of the monument. Now you just need to click on the green “map pin” marker button and drag it to the location where you took the photo. Click on that position and click on the OK button on the pop window, with a thumbnail of your photos. That’s it. So, within the accuracy of how google maps are mapped onto the geoid , which is a whole different story, I am fairly certain these cooridnates are fairly reliable. They also get nicely embededed in my photos EXIF data.

If you geotag several photos in your album, you can get a view of where they were taken by also having the places panel open as you view the album view open. I must admit I was a little disappointed there where not more ways to retrieve photos using geotags, maybe that will come. OK, there is a green map pin at the top of the Picasa window that retrieved all geotagged photos, but your can still only see them an album at a time.

Next I wanted to compare geotagging the same photo with flickr. I was pleasantly surpised that the hybrid abd satellite images know in yahoo maps is now more accurate that last time I looked. But the best scale representation I could get (you can see the kilometerr scale on the bottem left of my screen capture) is no where near as detailed as the google map equivalent, but I could strret the main street and guess about half way along. So maybe I will be within about 30 meters. Once you have save the location, your main photo display page will show a taken in location down under additional information of the right hand side.

I wanted to check the location accuracy but do you know what? You can’t see the actual coordinates for things you geotag in flickr, you can just see them on a map. So I still don’t really have a good comparison of accuracy. It is at the retrieving end that he difference in flickr win out. You can get a map of all your geotagged photos, explore the world or just for nearby photo by others, use the flickr api, or even via third party gadget & widgets (like mine, down on the right hand side of this blog).

By the way if your upload a photo to flickr, that is already geotagged in picasa, it is automatically give the map button.

Friday, October 09, 2009

This panorama is in the style of a David Hockney"Joiner",I liked the blue sunny sky with a few puffy clouds so I made this collage to the size to be my screen wallpaper (I have a collection of other wallpaper on flickr where they can be downloaded for free).

"Cubism was total-vision: it was about two eyes and the way we see things. Photography had the flaw of being one-eyed... My joke was that all ordinary photographs are taken by a one-eyed frozen man!" ...David Hockney

Hockney explored the multi-image collage as a way to express three artistic elements which a single photograph cannot have, namely layered time, space and story.

Thursday, October 01, 2009

Modern digital cameras with their large megapixel size can be a hassle for travellers. Unlike a film camera, where you just buy more film as you go, and get them processed when you get home.With a digital camera what do you do when your memory card fills up?

Before I begin remember Backup, ensuring you have a second copy of image incase the original is deleted, is different to Archiving, achieving dependable long term storage of an image.

Buy more memory cards? Well they are getting almost as cheap as film, once you pay for its processing. For example a cheapest 4GB SD card I can find at the moment (in Australia) cost around $20. Many older camera can only take 1GB SD cards, which cost around $12. The table below will give you a rough guide to how many photos in jpeg format, fit on various card sizes given the camera's megapixel size.

Megapixel

128MB

256MB

512MB

1GB

2GB

4GB

2

134

268

552

1119

2245

4494

3

120

240

490

996

2000

4000

4

60

119

245

497

999

1998

5

48

95

195

395

800

1595

6

44

88

180

366

735

1471

7

39

78

161

327

657

1314

8

35

69

143

290

582

1164

10

26

53

109

221

444

887

12

20

40

83

169

339

678

Write CDs at the local photo booth. Most modern photo kiosks, especially in areas frequented by backpackers, offer a service to write a CD from files on your memory card. Often this is very cheap if you get a few photos printed. Rather than carry the CD around, why not post it to yourself (using a protective cardboard CD pouch).Backpack drive, these are external disk drives, normally just temporarily connected to you computer(swapping between your home PC, laptop or notebook) via a USB connector. If you make sure this is relatively empty when you start you will have plenty of capacity for your trip.Today very large capacity 300 to 500GB are quiet affordable. It may be wise to invest a little more in a shock resistant model with its own travel case, as it will also be travelling with you.
USB Card Reader, even if you don't carry your own computer, having a suitable card reader will mean you could use the computers at a cyber cafe (but be warned not all of then will let you connect USB devices, sometimes they may charge you!) or those free library internet computers to transfer photos to your packback drive or even Skydrive. A new type of Multi-media storage device for photographer is appearing, a kind of hybrid photo frame, card reader & backpack storage. At around $600 plus for 40GB at the moment, they are not cheap, eg. ten 4GB will SD cards be less than half the cost. Epsom seem to be leading this market in Australia.
Finally use Jpeg Format (rather than RAW) and consider shooting at a lower pixel size (if your camera allows this).

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